Hi,

I've tried the DQ860MA external steppers with the smoothieboard and they work without any problems so far.

vimeo.com / 115509540

In my opinion the KL-5056D should work as well.
In the kelinginc.net / KL-5056D.pdf , page 4 figure 3 you can see how you have to wire the drivers to the ST,DIR,EN and GND pins of the smothieboard. The internal resistors are 270Ohm and calculated for 5VDC signals, as far as i know the smoothieboard outputs only 3.3V, but for my DQ860MA that was not a problem, the optocouplers get only 8mA in this case but it seems to be enough to switch them.

Bouni

I plan to use some 570 oz stepper motors on a vertical mill CNC conversion. I am trying to decide what stepper motor drivers to use. It seems that the DQ860MA Stepper Motor Driver is the only one that has been reported as working with the smoothieboard.

Pretty much any external driver with a step/direction interface will work with Smoothieboard.

In some cases the driver will want 5V input, and Smoothieboard outputs 3.3V, but generally the drivers are fine with 3.3V even if rated at 5V. If 3.3V is not sufficent it's trivial to use a level shifter to bump the 3.3V up to 5V.

So generally, the vast majority of external drivers work out of the box with Smoothieboard.

I personally use the CW5045 and am pretty happy with it.

I am interested in trying the digital steppers from Automation Technology, specifically the KL-5056D driver, which people have been happy with for this purpose. Do these drivers have any advantages or disadvantages relative to the DQ860MA? Will they even work with the smoothieboard?

Yes.
All of those drivers are very similar, and work with Smoothie.

Pretty much, if you read DIR+ DIR- EN+ EN- PUL+ PUL- on it, you know it'll work with Smoothieboard.

The current technology that people use for mill CNC conversions seems a bit nutty to me. They use the ethernet smooth stepper board to convert an ethernet signal to a parallel port in order to transmit the g-code from Mach 3/4 to the drivers.

Yeah that's just a relic of the 80s :)

Smoothie is the modern way to do it :)

I am using an ST5045/2M542 from Sain-Smart to drive a NEMA-23 stepper using the SmoothieBoard step/direction/enable signals. It works fine. I have also used a DM542 from China and it, too, worked fine. They seemed OK with smoothieboard's default 1 us pulse duration, but the driver manuals specify 10 us minimum (in conflict with the max step rate spec as 300 ksps), so I set the smoothieware pulse duration to 3us to have just a little margin over the default 1 us.

The Sain-Smart ST5045 and DM542 appear to be the same thing, only slightly different- it's one of those devices made by 20 different companies in China that are all more or less the same with tiny differences and all selling for about the same price. $35-40 in this case. Sain-smart calls it a 2M542, but their photos, their manual, and the part that arrives are labeled ST-M5045. You can find the same module selling all over ebay under 3 or 4 different part numbers, most containing a "542" somewhere.

I connected the ground of the driver module to the smoothie board ground (and the motor power supply ground), the - (negative/minus) inputs for step and direction on the driver module to ground, and then the + inputs for step/direction/and enable all went straight to the smoothieboard, no resistors required. I am running the motors from 32V supplies.

Well I've never tried it but apparently you can use Mach3 to control a Smoothieboard :)

Most of the G-codes you mention are related to writing G-code by hand.

That's not something our users do, so there is no big pressure to implement those ( though some of them are being implemented, we have canning cycles somewhere in a separate branch for example I think ).

Smoothie expects the user to do everything in CAM, which is fine for probably all hobby users, and for some professional users at least.

You bring up some good points. My concern about the Mach3/4 -> ethernet smoothstepper -> stepper controller is that it is clearly something of a kludge and there should be a more rational and cheaper setup at this point. On the other hand, as you point out, the lack of backlash compensation and tool offsets is a problem and the conversational features make it easier to do hand/custom work.

A lot of chinese manufacturers sell drivers with those part numbers, so I don't know what the T means, but they could be fairly different if they have come from different manufacturers.

It seems your DM542Ts may be duds. Do you have any way to verify they work at all? Have you tried manually stepping them (like connecting a button to the STP input?)

Is it possible the old drivers damaged the smoothieboard in some way? Have you tried swapping the working DM542s with the DM542Ts, just to eliminate that possibility?

If you've eliminated those possibilites (dud drivers, damaged smoothie), then it could be a logic level problem. The smoothieboard outputs 3.3V, and most external drivers expect 5V (though most apparently work fine with the 3.3V, but maybe yours dont)

I've been having trouble with external drivers too, still not 100% sure what, but my next test is to put a logic level shifter inbetween the board and the driver, because mine work, but miss steps every now and then.